Coating composition and method of using same



Patented Jan. 2, 1951 COATING COMPOSITION'AND METHOD or M USING SAME Nathan Sugarinan, Atlanta, Ga., and Foster M. Fryman, Newport Beach, Gal-ii, assignors to The Standard Re ister a corporation of Ohio .1

ompany, Dayton, Ohio,

No Drawing. Application January 16, 1947,

This invention relates to'a com-position which when appl ed as a liquid coating upon -an object will set and harden quickly. A It is an object of this invention to prepare a coating composition of a liquid-consistency, which when. applied as a thin film on an object may be hardened by a short exposure to gaseous sulfur dioxide With or without the application of heat. It is more particularly an object of this invention to prepare a film-forming composition for carbon block-out which will set and harden quickly.

Other objects of this invention and the various advantages will, in part, beobvious, and will,'in part, appear hereinafter as the description pro- 'ceeds.

According to our invention these and other objects are attained by forming a liquid, rapidly hardening coating'composition characterized by a liquid, partial condensate of furane-type alde- Hyde and an aryl diamine, the ratios'of the former to the latter being substantially 2:1 to 4:1. Other film-forming materials may be present such as cel ulose ethers and -esters, synthetic W resins, plasticizers and wetting agents. it

The'preferred aryl diamine is 2,4-diaminotoluene. The mo'stre'adily-available furane-type aldehyde is furfural. However heat polymerized furfural is the preferredcyclic aldehyde because it allows a faster hardening after the coating composition has been applied as a film. The presence of a sma l amount of iodine to the liquid mixture increases the speed of hardening. Instead of ZA-diaminotoluene other aryl diamines may be employed. Examples of these are: phenvlene diarnine and the xylenes diamines. Instead of furfural or polymerized furfural other furane-type aldehydes such as methyl furfural, ethyl furfural maybe used.

-' 'The'furfural has a dual role in the composition.

When furfural is mixed with the amine heat is engendered. A condensation of some type takes place between these two components. The excess furfural also acts as a solvent or diluent for this condensate and the other components of the filmforming composition. 'Furfural may be used in ratios of 2:1, 3:1 or 4:1 in reference to.the 2,4-diaminotoluene. The lastratio is the preference. Larger amounts of furfural could be employed but the drying time would be decreased due to th excess solvent which must be volatilized. 1 .The mixing of the furfural with the aryl diami'ne engenders heat, which causes a more 'rapid' condensation; this isman fested by a-subsequent thickening or increase of viscosity" of: .thefinal g Serial No'. 722,4 0

14 Claims. (01. 117-452) 2 mix- But such a-phy'sical property makes the final product more diflic'ult to apply in a thin film.- However, by cooling the mixture during the addition-of the furfural to the amine, condensation is arrested. =A homogeneous. mixture canbe thus secured; .This can be applied in its nonvisco'us state or' condition. After the coating mixture is applied and a film is formed on an object, hardening thereof. takes place regardless of whether they furfural and amine weremixedlwith or without coo1ing.-.During this setting or drying period,,.which is of the order of 30seconds or less, it is our belief that condensation of. the diamine, with the furfural takes place or continues to completion where in,- itiated or partially carried out previously.

The furfural and diamine may be brought .togethersin the absence of other components which are employed in the coating composition. Thisi's true whether the mixture .of these two'compo nents is cooled, or the heat from .the exothermic reaction is not dissipated or even where heat is applied. 3

As stated supra, it ispreferred to employ fur.- i ural which hasbeen pre polymerized by heating for a period of time: It has been found that the use of polymerized furfural in the coating composition allowsa faster hardening as compared with non-polymerized furfural. I V A convenient way to s cure polymerized fur fural is' by. heating it with 0.1% of anhydrous aluminum chloride for four hours and then coolin qu c l p i j In order more p-articularly to describe the pres; ent invention, there fol ow two typical embodimerits; It is to beunders tood that'the features asset Iorth in thefembodiments are by wayff illustration only and are not to be construedin alimiting sense.

Example 1 I Ingredients: Partsby weight Heat polymerized furfural 20' Tetrahydra'furfural phthalate :12 Emulsifier #87 1 1 An organic phosphorus derivative containing long chain alkyl' groups as W011 {1$ water solub lr-rlng groups; v A11 alkyd resin made with non-drying oils and containinf; approximately 49 plithalic anhydride.

and .the furane-type aldehyde.

but the composition should be cooled during the addition of the 2,4-diaminotluene.

This composition may be printed as a film on the carbon paper, and this film will harden in seconds when placed inan atmosphere oflsulfur dioxide.

1 An organic phosphorus derivative containing long chain alk l crouns as ell as water solubilir'lng groups An alkyd resin made with non-dryin oils and containing approximately 49% phthalic anhydride.

The constituents are dnixed in the order given above. The same precaution as to temperature conditions set outfin Example 1 should "be observed.

'Wliilein theabove examples a certain ordero'f mixing hasbeenspecified, this s not critical,although preference'mayb'e held becauseof mechanical aspects or even'to govern the degree of condensation between the amine 'and'it-healdehyde. The components may in'factbe mixed simultaneously.

.'As mentionedsupraand'ias' disclosed 'more'spe- .cific'allyin' the examples,'other 'film forining con- 'stituen'ts maybe present than the aryl .dia'mine 'At least on of each "of the previously mentionedtypesof'these materials maybe incorporated.

Various 0611111086 esters may be used .suchfas cellulose nitrate, cellulose acetate, "cellulose 'formate, cellulose 'butyrate and cellulose propionate.

.Examples of cellulose ethers which may be .used are ethyl cellulose, methyl cellulose and benzyl cellulose.

.llariousplasticizers ralsomay be used, such as .triphenyl phosphate, tricresyl phosphate, 't'riacetin, camphonp-tdlueneor xylene'sulphonamide, dr'ethvl ,p'hthalate, dibutyl ,phthalate and Various resins may .be used. Illustrative of the synthetic resins are the phenol-formaldehyde resins (Bakelite type) and alkyd resins. The term phenol isin the references to include, besides hydroxybenzol (CsHsOH), all "homologu'e's and also polyphenols such as resorci'n and the like and theenaphthols andtheirderivatives with airee hydroXyl-group. Also compoundsh'aving free hydroxyl .groups such as methylene .diphenol CHafCsI-IiOHlz, .diphenylol iprfopan'e CH3)2'C(C6H4O'H)z, and similar compounds ,in which the phenyl group is replaced by the naphthyl group may paused to prepare the resin.

Pigments or dyes or other materials -.may be "added to .the icomposition t'o impart such :properties .as are desired in the finished product, as

is well understood in the liquid coating art.

Mixturesof these several group representative materials may be *conip'oun'ded.

The invention presents advantages "over the present liquid coating compositions which are .printed -as a film on carbon paper because formulae 'of the preferred -'ingredients in chosen ratios dry in a matter ofsec'onds in :an fatmosphere of sulfur dioxide or other acidic gases. It has other' uses inl-th'e ifield 'o'f liquidcoating -;c"'ompositions. 2ft can be applfe'd a sum to :-:the

chosen objects by spraying, dipping or brushing.

Itis apparent that many widely difierent embodiments of this invention may be made without departing from the spirit and scope thereofand, therefore, is notto-be limited except as indicated by the appended claims.

We claim:

:1. A liquid, rapid drying composition comprising a liquid, partial condensate of polymerized .iurfural and 'an'aromatic diamine, wherein the two amino groups are substituted directly on the aromatic nucleus,atlie ratio of the polymerized furfural'to the aromatic diamine being substantially 2:1-substantially 4:1, a member of the "group-consisting of cellulose ethers and cellulose -esters, a plasticizer and a Wetting agent, said I'composition when applied as a thin film being capable of hardening in a period of not over seconds by exposure to .an atmosphere of sulfur dioxide.

2. "A 'liquid, ra'pid' drying "composition-comprising "-a liquid, partial -'eondensate of furfural *and 2,4-diaminotoluene, theratiobf the formerto the latter "being substantially 2:1 substantially 451, 21 membero f the group consisting of cellulose ethers "and cellulose esters, a plasticizer and "a wetting-agent, said composition when applied-as a thin'filmbeing "capable of hardening in a perio 'd of not over 30 'secondsby exposure toan'atmosphere of sulfur dioxide.

"3. The process of coating comprising the steps of forming a filmof a liquid .compositionico'n'rprising a liquid, partial condensate of'polymerizfed A. .The process of coatingcomprising thesteps of forming 'a film :of (a .liquid composition. comprising a liquid,partial-condensate ofpol-ymerized 1' urfural and 2;4-diaminotoluene in the component ratios 2:1- -.4;-1- substantially, a member of the group consisting of cellulose ethers and celluloseestersgamlasticizer, a-resin ands-a wetting agent, upon carbon paper, --thereafter .exposing'said filmtosan 'atmosphere of an-acidi'c gas'until-it harde'ns.

- 5. The process of coating comprising thesteps of forming a film of a liquid composition comprising a liquid, partial condensate'of a menober of the group consisting of *furfural, polymerized furfural and a short-chainalkyl substituted fu'rfural with an aromatic diamine in the component ratios of "substantially 2 1-4 :'1,'upon' carbon :paper, the said diamine having two amino groups directly substituted on the aromatic nucleus thereafter vexposing said film ':to an acidic gas untili't5hardens.

6. "The proce-s'svof icoating comprising athexsteps of forming 'a' film ofa liquid composition "cornprising 'a liquid, partial "condensate of -a member: of the group consisting "of furfural, "polymerized fu'rfural and 'a short. chain 'alkyl substituted -fu1ifii1r-al with :2;4-:diaminotoluene "in "the :component ratiost'of substantially 2191-1411, up'Qn'Jcarb onipapen'thereaft'er exposing said film to an acidic ga's -until it hardens.

7. "A liquid, rapidly hardening coating '=com'- position :comprising a liquid, partial condensate of a member'ofithe'group consisting-:offurfural, polymerized furfural and a :short chain .alkyl substituted ,rfuriural, with .;an aromatic :diamine wherein the -tv'vo amino group's are substituted fdirectly son the aromatic nucleus, :the ratios as 5 the aldehyde to the diamine being substantially 2:1 to 4:1.

8. A liquid, rapidly hardening coating composition comprising a liquid, partial condensate of a member of the group consisting of furfural, polymerized furfural and a short chain alkyl substituted furfural, with 2,4-diaminotoluene, the

ratios of the aldehyde to the diamine being substantially 2:1 to 4:1.

9. A liquid, rapidly hardening coating composition comprising a liquid, partial condensate of polymerized furfural and an aromatic diamine wherein the two amino groups are substituted directly on the aromatic nucleus, the ratios of the aldehyde to the diamine being substantially 2:1 to 4:1.

10. A liquid, rapidly hardening coating composition comprising a liquid, partial condensate of polymerized furfural and 2,4-diaminotoluene, the ratios of the aldehyde to the diamine being substantially 2:1 to 4:1.

11. A liquid, rapidly hardening composition comprising a liquid, partial condensate of a member of the group consisting of furfural, polymerized furfural and a short chain alkyl substituted furfural, with an aromatic diamine wherein the two amino groups are substituted directly on the aromatic nucleus, the ratios of the aldehyde to the diamine being substantially 2:1 to 4:1, and a member of the group consisting of cellulose ethers and cellulose esters, a plasticizer, and a wetting agent, the said partial condensate exceeding by weight any of these other recited components.

12. A liquid, rapidly hardening composition comprising a liquid, partial condensate of a member of the group consisting of furfural, polymerized iurfural and a short chain alkyl substituted furfural, with 2,4-diaminotoluene, the ratios of the aldehyde to the diamine being substantially 2:1 to 4:1, and a member of the group consisting of cellulose ethers and cellulose esters, a plasticizer, and a wetting agent, the said partial condensate exceeding by weight any of these other recited components.

13. A liquid, rapidly hardening coating composition comprising a liquid, partial condensate of a member of the group consisting of furfural, polymerized furfural and a short chain alkyl substituted furfural, with an aromatic diamine wherein the two amino groups are substituted directly on the aromatic nucleus, the ratios of the aldehyde to the diamine being substantially 2:1 to 4:1, and a small amount of iodine.

14. A liquid, rapid hardening composition comprising a liquid, partial condensate of a member of the group consisting of furfural, polymerized furfural and a short chain alkyl substituted furfural, with 2,4-diaminotoluene, the ratios of the aldehyde to the diamine being substantially 2:1 to 4:1, and a small amount of iodine.

NATHAN SUGARMAN, FOSTER M. FRYMAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

5. THE PROCESS OF COATING COMPRISING THE STEPS OF FORMING A FILM OF A LIQUID COMPOSITION COMPRISING A LIQUID, PARTIAL CONDENSATED OF A MEMBER OF THE GROUP CONSISTING OF FURFURAL, POLYMERIZED FURFURAL AND A SHORT CHAIN ALKYL SUBSTITUTED FURFURAL WITH AN AROMATIC DIAMINE IN THE COMPONENT RATIOS OF SUBSTANTIALLY 2:1-4:1, UPON CARBON PAPER, THE SAID DIAMINE HAVING TWO AMINO GROUPS DIRECTLY SUBSTITUTED ON THE AROMATIC NUCLEUS THEREAFTER EXPOSING SAID FILM TO AN ACIDIC GAS UNTIL IT HARDENS.
 7. A LIQUID, RAPIDLY HARDENING COATING COMPOSITION COMPRISING A LIQUID, PARTIAL CONDENSATE OF A MEMBER OF THE GROUP CONSISTING OF FURFURAL, POLYMERIZED FURFURAL AND A SHORT CHAIN ALKYL SUBSTITUTED FURFURAL, WITH AN AROMATIC DIAMINE WHEREIN THE TWO AMINO GROUPS ARE SUBSTITUTED DIRECTLY ON THE AROMATIC NUCLEUS, THE RATIOS OF THE ALDEHYDE OF THE DIAMINE BEING SUBSTANTIALLY 2:1 TO 4:1. 